1
|
Balint S, Schwartz M, Fowler DN, Linnekogel S, Clemons SC, Burkemper LK. Experimental assessment of elemental analyzer isotope ratio mass spectrometry normalization methodologies for environmental stable isotopes. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2024; 38:e9837. [PMID: 38923072 PMCID: PMC11284645 DOI: 10.1002/rcm.9837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 05/21/2024] [Accepted: 05/22/2024] [Indexed: 06/28/2024]
Abstract
RATIONALE In stable isotope mass spectrometry, isotope delta values are normalized to internationally recognized reference scales using a combination of certified and in-house isotope reference materials. Numerous techniques exist for performing this normalization, but these methodologies need to be experimentally assessed to compare their effect on reproducibility of isotope results. METHODS We tested normalization methods by the number of reference materials used, their matrix, their isotope range, and whether normalization required extrapolating beyond the isotope range. We analyzed eight commercially available isotope reference materials on a ThermoFinnigan Delta-V isotope ratio mass spectrometer (IRMS) and an Elementar VisION IRMS for nitrogen and carbon isotope composition via solid combustion with an elemental analyzer and computed every possible isotope normalization (n = 612). Additionally, we assessed how sample matrix affected linearity effects on both instruments using five in-house reference materials. RESULTS Normalizations exhibited the best performance when the reference materials spanning an isotope range of at least 20‰ were matrix matched with the samples and did not require extrapolation beyond the calibration curve. When these conditions were not met, the number of reference materials used had a significant effect on accuracy, with normalizations composed of two reference materials exhibiting particularly inconsistent performance at isotope ranges below 20‰. Linearity effects were found to exceed instrument precision by two orders of magnitude irrespective of matrix type and were not predicted by working gas diagnostics. CONCLUSIONS Interlaboratory comparability of isotope results is improved when operators of elemental analyzer isotope ratio mass spectrometry (EAIRMS) systems select reference materials spanning an isotope range of at least 20‰. Additionally, using three or more isotopic reference materials, avoiding extrapolation beyond the range of the normalization curve, and matching the matrix of the reference materials to the samples improve normalizations.
Collapse
Affiliation(s)
- Sawyer Balint
- ORISE Participant, U.S. EPA Atlantic Coastal Environmental Sciences Division, Narragansett, RI. 02882
| | - Morgan Schwartz
- U.S. EPA Atlantic Coastal Environmental Sciences Division, Narragansett, RI. 02882
| | - Drew N. Fowler
- U.S. Geological Survey, Louisiana Cooperative Fish and Wildlife Research Unit, Baton Rouge, LA. 70810
| | - Stella Linnekogel
- UK Centre for Ecology & Hydrology Lancaster, Library Avenue, Bailrigg, Lancaster, LA1 4AP, United Kingdom
| | | | - Laura K. Burkemper
- Center for Stable Isotopes, University of New Mexico, Albuquerque, NM 87131
| |
Collapse
|
2
|
Schnabel F, Barry KE, Eckhardt S, Guillemot J, Geilmann H, Kahl A, Moossen H, Bauhus J, Wirth C. Neighbourhood species richness and drought-tolerance traits modulate tree growth and δ 13 C responses to drought. PLANT BIOLOGY (STUTTGART, GERMANY) 2024; 26:330-345. [PMID: 38196270 DOI: 10.1111/plb.13611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 11/24/2023] [Indexed: 01/11/2024]
Abstract
Mixed-species forests are promoted as a forest management strategy for climate change adaptation, but whether they are more resistant to drought than monospecific forests remains contested. In particular, the trait-based mechanisms driving the role of tree diversity under drought remain elusive. Using tree cores from a large-scale biodiversity experiment, we investigated tree growth and physiological stress responses (i.e. increase in wood carbon isotopic ratio; δ13 C) to changes in climate-induced water availability (wet to dry years) along gradients in neighbourhood tree species richness and drought-tolerance traits. We hypothesized that neighbourhood species richness increases growth and decreases δ13 C and that these relationships are modulated by the abiotic (i.e. climatic conditions) and the biotic context. We characterised the biotic context using drought-tolerance traits of focal trees and their neighbours. These traits are related to cavitation resistance versus resource acquisition and stomatal control. Tree growth increased with neighbourhood species richness. However, we did not observe a universal relief of water stress in species-rich neighbourhoods. The effects of neighbourhood species richness and climate on growth and δ13 C were modulated by the traits of focal trees and the traits of their neighbours. At either end of each drought-tolerance gradient, species responded in opposing directions during dry and wet years. We show that species' drought-tolerance traits can explain the strength and nature of biodiversity-ecosystem functioning relationships in experimental tree communities experiencing drought. Mixing tree species can increase growth but may not universally relieve drought stress.
Collapse
Affiliation(s)
- F Schnabel
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
- Systematic Botany and Functional Biodiversity, Leipzig University, Leipzig, Germany
- Chair of Silviculture, Faculty of Environment and Natural Resources, University of Freiburg, Freiburg, Germany
| | - K E Barry
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
- Systematic Botany and Functional Biodiversity, Leipzig University, Leipzig, Germany
- Ecology and Biodiversity, Department of Biology, Institute of Environmental Biology, Utrecht University, Utrecht, Netherlands
| | - S Eckhardt
- Systematic Botany and Functional Biodiversity, Leipzig University, Leipzig, Germany
| | - J Guillemot
- CIRAD, UMR Eco&Sols, Piracicaba, Brazil
- Eco&Sols, Univ Montpellier, CIRAD, INRAE, Institut Agro, IRD, Campus SupAgro, Montpellier, France
- Department of Forest Sciences, ESALQ, University of São Paulo, Piracicaba, Brazil
| | - H Geilmann
- Max Planck Institute for Biogeochemistry, Jena, Germany
| | - A Kahl
- Systematic Botany and Functional Biodiversity, Leipzig University, Leipzig, Germany
| | - H Moossen
- Max Planck Institute for Biogeochemistry, Jena, Germany
| | - J Bauhus
- Chair of Silviculture, Faculty of Environment and Natural Resources, University of Freiburg, Freiburg, Germany
| | - C Wirth
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
- Systematic Botany and Functional Biodiversity, Leipzig University, Leipzig, Germany
- Max Planck Institute for Biogeochemistry, Jena, Germany
| |
Collapse
|
3
|
Chesson LA, Berg GE, Edwards AJ, Chau TH, Low L, Johnson DL, Tichinin AC. Forensic application of isotope ratio mass spectrometry (IRMS) for human identification. Sci Justice 2024; 64:28-37. [PMID: 38182310 DOI: 10.1016/j.scijus.2023.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 11/02/2023] [Accepted: 11/21/2023] [Indexed: 01/07/2024]
Abstract
Application of isotope ratio mass spectrometry (IRMS) to skeletal remains has become an important tool to investigate human behavior and history. Isotopic variations in collagen, enamel, and keratin reflect variations in an individual's diet and drinking water. Since food and water sources typically are geographically linked, isotope testing can assist in forensic identification by classifying remains to a likely geographic or population origin. If remains are commingled, differences in diet or geographic origin also can support their separation. The usefulness of IRMS in forensic science is dependent on the underlying quality and surety of the isotope test results; in other words, we need to understand their reliability in interpretations. To take ownership of isotopic data quality, we recommend asking a series of questions:Here, we use data collected during the buildout and accreditation of an isotope testing program at the Defense POW/MIA Accounting Agency (DPAA) to answer the above questions for the forensic application of IRMS for human identification. While our primary focus is on the preparation and analysis of bone collagen, the questions above should be considered whenever isotope testing is used in forensic casework. Whether the populations of interest are drugs or humans, olives or explosives, users need to evaluate their isotopic data and interpretations to ensure they are scientifically sound and legally defensible.
Collapse
Affiliation(s)
- Lesley A Chesson
- Defense POW/MIA Accounting Agency (DPAA) Laboratory, 590 Moffet Street, Bldg 4077, Joint Base Pearl Harbor Hickam, HI 96853, USA.
| | - Gregory E Berg
- Defense POW/MIA Accounting Agency (DPAA) Laboratory, 590 Moffet Street, Bldg 4077, Joint Base Pearl Harbor Hickam, HI 96853, USA
| | - Amelia J Edwards
- SNA International Contractor, working under contract with the DPAA, 500 Montgomery Street, Ste 500, Alexandria, VA 22314, USA
| | - Thuan H Chau
- SNA International Contractor, working under contract with the DPAA, 500 Montgomery Street, Ste 500, Alexandria, VA 22314, USA
| | - Lyndi Low
- SNA International Contractor, working under contract with the DPAA, 500 Montgomery Street, Ste 500, Alexandria, VA 22314, USA
| | - Daniel L Johnson
- SNA International Contractor, working under contract with the DPAA, 500 Montgomery Street, Ste 500, Alexandria, VA 22314, USA
| | - Alina C Tichinin
- SNA International Contractor, working under contract with the DPAA, 500 Montgomery Street, Ste 500, Alexandria, VA 22314, USA
| |
Collapse
|
4
|
Dunn PJH, Skrzypek G. Perspective: Hidden biases in isotope delta results and the need for comprehensive reporting. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2023; 37:e9623. [PMID: 37706430 DOI: 10.1002/rcm.9623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/01/2023] [Accepted: 08/03/2023] [Indexed: 09/15/2023]
Abstract
Measurements of stable-isotope composition on an isotope-delta scale can be subject to bias between laboratories or over time within a single laboratory. This bias can arise not just from differences in method protocol but also from changes in reporting guidelines, or even to the isotope-delta scales themselves. Without a clear description of method protocols, including all sample preparation steps, instrumental parameters and settings, data processing including calibration of results and estimation of measurement uncertainty, the traceability and comparability of isotope-delta values cannot be assured as bias(es) may remain hidden. To address this need, there are now clear guidelines published by IUPAC for reporting isotope-delta values for the "light" elements hydrogen, carbon, nitrogen, oxygen and sulfur.1 We recommend that authors and reviewers adhere to those guidelines when preparing and reviewing future publications.
Collapse
Affiliation(s)
- Philip J H Dunn
- National Measurement Laboratory, LGC Limited, Teddington, UK
| | - Grzegorz Skrzypek
- West Australian Biogeochemistry Centre, School of Biological Sciences, The University of Western Australia, Crawley, Western Australia, Australia
| |
Collapse
|
5
|
Skrzypek G, Allison CE, Böhlke JK, Bontempo L, Brewer P, Camin F, Carter JF, Chartrand MMG, Coplen TB, Gröning M, Hélie JF, Esquivel-Hernández G, Kraft RA, Magdas DA, Mann JL, Meija J, Meijer HAJ, Moossen H, Ogrinc N, Perini M, Possolo A, Rogers KM, Schimmelmann A, Shemesh A, Soto DX, Thomas F, Wielgosz R, Winchester MR, Yan Z, Dunn PJH. Minimum requirements for publishing hydrogen, carbon, nitrogen, oxygen and sulfur stable-isotope delta results (IUPAC Technical Report). PURE APPL CHEM 2022. [DOI: 10.1515/pac-2021-1108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Abstract
Stable hydrogen, carbon, nitrogen, oxygen and sulfur (HCNOS) isotope compositions expressed as isotope-delta values are typically reported relative to international standards such as Vienna Standard Mean Ocean Water (VSMOW), Vienna Peedee belemnite (VPDB) or Vienna Cañon Diablo Troilite (VCDT). These international standards are chosen by convention and the calibration methods used to realise them in practice undergo occasional changes. To ensure longevity and reusability of published data, a comprehensive description of (1) analytical procedure, (2) traceability, (3) data processing, and (4) uncertainty evaluation is required. Following earlier International Union of Pure and Applied Chemistry documents on terminology and notations, this paper proposes minimum requirements for publishing HCNOS stable-isotope delta results. Each of the requirements are presented with illustrative examples.
Collapse
Affiliation(s)
- Grzegorz Skrzypek
- West Australian Biogeochemistry Centre, School of Biological Sciences, The University of Western Australia , Crawley , WA , Australia
| | - Colin E. Allison
- Commonwealth Scientific and Industrial Research Organisation, Oceans and Atmosphere , Aspendale , VIC , Australia
| | | | | | - Paul Brewer
- National Physical Laboratory , Teddington , UK
| | | | - James F. Carter
- Queensland Health Forensic and Scientific Services , Archerfield , Australia
| | | | | | | | - Jean-François Hélie
- Geotop & Département des sciences de la Terre et de l’atmosphère, Université du Québec à Montréal , Montreal , Canada
| | - Germain Esquivel-Hernández
- Stable Isotopes Research Group and Water Resources Management Laboratory, Universidad Nacional Costa Rica , Heredia , Costa Rica
| | - Rebecca A. Kraft
- National Institute of Standards and Technology, United States Department of Commerce , Gaithersburg , MD , USA
| | - Dana A. Magdas
- National Institute for Research and Development of Isotopic and Molecular Technologies , Cluj-Napoca , Romania
| | - Jacqueline L. Mann
- National Institute of Standards and Technology, United States Department of Commerce , Gaithersburg , MD , USA
| | - Juris Meija
- National Research Council Canada , Ottawa , ON , Canada
| | - Harro A. J. Meijer
- Centre for Isotope Research, University of Groningen , Groningen , Netherlands
| | - Heiko Moossen
- Max Planck Institute for Biogeochemistry , Jena , Germany
| | - Nives Ogrinc
- Department of Environmental Sciences , J. Stefan Institute , Ljubljana , Slovenia
| | - Matteo Perini
- Fondazione Edmund Mach , San Michele all’Adige , Italy
| | - Antonio Possolo
- National Institute of Standards and Technology, United States Department of Commerce , Gaithersburg , MD , USA
| | | | - Arndt Schimmelmann
- Department of Earth and Atmospheric Sciences , Indiana University , Bloomington , IN , USA
| | - Aldo Shemesh
- Department of Earth and Planetary Sciences , The Weizmann Institute of Science , Rehovot , Israel
| | - David X. Soto
- International Atomic Energy Agency , Vienna , Austria
| | | | - Robert Wielgosz
- Bureau International des Poids et Mesures , Sevres Cedex , France
| | - Michael R. Winchester
- National Institute of Standards and Technology, United States Department of Commerce , Gaithersburg , MD , USA
| | - Zhao Yan
- Institute of Quality Standard and Testing Technology for Agri-Products, Chinese Academy of Agriculture Sciences , Beijing , China
| | | |
Collapse
|